FIVE AMP VOLTAGE REGULAR TO-220's or TO-5's ?

MEXICOWANDERER wrote:
I'm running into a situation where the hotter than hell temperatures here make fixed voltage charging of -expensive- lithium ion batteries and nickel metal hydride batteries iffy. I would like to back the voltage off 2-3%

Also, those little monsters are not all of like construction. Is there a website that has charts for these cells, and recommendations for temperature compensation?

The issue is power outages, running a 4024 inverter just to charge batteries, and finding a sixty dollar lithium battery (tool) that lasts only a year with perhaps ten hours of use on it. I am referring to new DeWalt stuff so quality is not an issue. It's either back the maintenance voltage down or use a cycle timer. It's be nice to find an easy to program, inexpensive cycle timer.

Some of my NiMH stuff will self-discharge to zero in a month or two. Crappy circuit design allows the float voltage circuit to fail and even though a charge indicator LED glows green, the battery is deader than a stick. The damned thing needs to have it's switch recycled daily. Aghhhh!

With low loads, the Trace is giving me efficiency somewhere in the high seventies - stupid to use 80% of battery wattage energy to maintain an inverter circuit. Hence all these DC to DC questions. Summer outages are due to storms as in overcast skies, so battery recharging has to be done via generator, four dollar a gallon gasoline or diesel and a 62 mile round trip to go get it. I gotta get 600 - 800 watts worth of panels up on the roof, but summer thunderstorms, tropical storms, hurricanes can cut panel output 95% for days on end.

Umm.. you do realize that they DO make 12V CAR chargers for many cordless tools?

Here is one.. Dewalt Car Charger

It would be foolish to attempt to home brew your own charger or mess with the charging voltage of ANY Li-ion battery. In fact those batteries have a built in circuit which can disconnect the battery in case of over charge or over discharge currents.. Those protection circuits are there to protect YOU from a very nasty fire hazard.

And YES, I have personally seen the affects of a Li-ion battery on a device which the charging circuit malfunctioned... Burned a person and melted the device..

I STILL love my old school Makita 9.6V cordless drill, saw, sander and flashlight which used Nicad batteries.. Dead on reliable, you couldn't give me one of these newer higher voltage cordless ones even if you gave me a million dollars too boot.. These newer high voltage cordless items are not designed for a long life of the battery...

A I said, there is a modification (External) to the Progressive Dynamics Intella-power 9100 line that lets you control the voltage rather than the internal regulator.. Basically it's a pot and a plug and some wires.

What I can not tell you is how to wire the plug to the pot. You can find it in a forum message perhaps 3 or 4 years old.. I just did not record the diagram.

If you want to build your own... Well, I am not that good at switching supplies but there are modules on the market that can handle it and are not that big.

I'm running into a situation where the hotter than hell temperatures here make fixed voltage charging of -expensive- lithium ion batteries and nickel metal hydride batteries iffy. I would like to back the voltage off 2-3%

Also, those little monsters are not all of like construction. Is there a website that has charts for these cells, and recommendations for temperature compensation?

The issue is power outages, running a 4024 inverter just to charge batteries, and finding a sixty dollar lithium battery (tool) that lasts only a year with perhaps ten hours of use on it. I am referring to new DeWalt stuff so quality is not an issue. It's either back the maintenance voltage down or use a cycle timer. It's be nice to find an easy to program, inexpensive cycle timer.

Some of my NiMH stuff will self-discharge to zero in a month or two. Crappy circuit design allows the float voltage circuit to fail and even though a charge indicator LED glows green, the battery is deader than a stick. The damned thing needs to have it's switch recycled daily. Aghhhh!

With low loads, the Trace is giving me efficiency somewhere in the high seventies - stupid to use 80% of battery wattage energy to maintain an inverter circuit. Hence all these DC to DC questions. Summer outages are due to storms as in overcast skies, so battery recharging has to be done via generator, four dollar a gallon gasoline or diesel and a 62 mile round trip to go get it. I gotta get 600 - 800 watts worth of panels up on the roof, but summer thunderstorms, tropical storms, hurricanes can cut panel output 95% for days on end.

wa8yxm wrote:
Ah, I think I see what you want.. A switching power supply will meet your needs. Try a Progressive Dynamics 9100 or 9200 plug in models.

The 9100, out of the box, is a single stage converter, it puts out 13.6 (And yes there is a way to adjust it though It has been a while since I saw the instructions) Unless you plug in the optional Charge Wizard, In which case it becomes basically a 9200, which is a 3-stage plus converter

The smallest one is I think capable of 45 amps. (9145/9245) but I could be wrong.. this would be about right for a pair of Group 24 batteries.

My coach has a 9180 with wizard.. One of the more interesting things I have found is a couple of times before I went Full time, I'd come out to use the Ham Radios here in the RV. The radio worked fine, no evidence of anything wrong with the power source.. and the batteries were,,, absent, due to having accidentally hit the disconnect switch (I finally put a guard on that switch).

The 9180 is that well filtered.

They also make a 9130...

pd 9130

Ah, I think I see what you want.. A switching power supply will meet your needs. Try a Progressive Dynamics 9100 or 9200 plug in models.

The 9100, out of the box, is a single stage converter, it puts out 13.6 (And yes there is a way to adjust it though It has been a while since I saw the instructions) Unless you plug in the optional Charge Wizard, In which case it becomes basically a 9200, which is a 3-stage plus converter

The smallest one is I think capable of 45 amps. (9145/9245) but I could be wrong.. this would be about right for a pair of Group 24 batteries.

My coach has a 9180 with wizard.. One of the more interesting things I have found is a couple of times before I went Full time, I'd come out to use the Ham Radios here in the RV. The radio worked fine, no evidence of anything wrong with the power source.. and the batteries were,,, absent, due to having accidentally hit the disconnect switch (I finally put a guard on that switch).

The 9180 is that well filtered.

Vicor has modules specifically for battery charger circuits. I believe they have a version for 120VAC input. They are stackable to a point.

Or This

Even if such a device existed, it would not be practical. Going from 120 volt to 12 volt is a huge voltage drop. 5 amps would mean a load of 60 watts on the output, but you would be pulling 600 watts on the input. The most efficient way of doing this would be a DC-to-DC converter.

I was hoping to find a high voltage DO-5 case device.

Regulated warts and bricks are nice. Sure like to find a source of really affordable higher amperage ones. I did find sources to manufacture affordable 16.0 volt regulated, 5.0 and 11 amp battery desulfation units (under 75 dollars including a wind up timer).

Short answer is yes, You can indeed find a higher power regulator.. I have, in the past, designed them. You will find all the information you need to build one from scratch in most any edition of the ARRL Amateur Radio Handbook which you can obtain from www.arrl.org - Store

I have the 100th annerversery edition as well as 2 or 3 more. here. I built my first one back in the 70's.. I think I still have it.

How about a wall wart?

I can't think of any power supply circuit that would work without a transformer and rectifier circuit.